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No. 67 








(Including Control of Internal and External Parasites) 

Canadian sheep-breeders are in the fortunate position of not having to 
contend with many of the infectious diseases which frequently scourge flocks in 
other parts of the world. In Eastern Canada the major problems are the 
diseases due to internal parasites, and pregnancy disease. In range sheep in 
the Western Provinces, goitre, haemorrhagic septicaemia (shipping fever), con- 
tagious ecthyma (sore-mouth), and intestinal parasites may cause losses. 

Miscellaneous Conditions 

Mineral Deficiency (including goitre). — In most districts a mineral 
mixture as a supplement to other feed is necessary for maximum growth and 
development, and this can usually be prepared so that it is adequate for the 
prevention of goitre in lambs. However, in those regions where goitre is pre- 
valent, pregnant ewes should be given one grain of potassium iodide per animal 
daily in the drinking water. A recommended mineral mixture for sheep is: — 

Bonemeal or bone char. 


Potassium iodide 

67 lb. 

33 lb. 

3 oz. 

Mix the first two ingredients, then dissolve the iodide in water and sprinkle 
it over the mixture. Leave it in front of the animals at all times. If bonemeal 
is unobtainable because of war needs, a commercial mixture as prepared for 
dairy cattle can be used. 

If monocalcium phosphate can be bought with a guarantee of freedom from 
harmful amounts of fluorine, the following mixture can be prepared in the 
manner described above. 

Monocalcium phosphate 

Ground limestone 


Potassium iodide 

15 lb. 

51 lb. 

34 lb. 

3 oz. 

There is suggestive evidence that a deficiency of copper may cause a 
weakness of lambs colloquially known as " sway-back ". In districts where this 
occurs the addition of four ounces of powdered copper sulphate well mixed into 

Published by Authority of Honourable J. G. Gardiner,- Minister of Agriculture. Ottawa. 1942. 
50M— 6303— 10 :42 




the other ingredients previously mentioned might be beneficial. In districts 
such as parts of Alberta where cobalt is deficient, local recommendations per- 
taining to it should be followed. 

Pregnancy Disease.— This is a continual source of loss to some sheen 
breeders, and m certain years it has caused the deaths of as many as ten per cent 
of the ewes in certain purebred flocks on rich diets. The affected animals show 
symptoms usually about three weeks before lambing time; they are reluctant 
to move even when approached, and are partly blind. The disease progresses 
and it the lambs are not born within two or three davs the ewes will die The 
livers of dead ewes are pale yellow in colour, which is due to an excess of' fat 

The best preventive is a balanced diet for pregnant ewes, complete with 
adequate roughage, accompanied by plenty of exercise. When animals show 
signs ol the disease the owner should immediately call a veterinarian, who can 
frequently offset the serious effects of this disease by proper treatment. 

Hemorrhagic Septicaemia (Shipping Fever).— This disease does not 
occur frequently under farm conditions, since it requires some weakening 
influence, such as hunger, fatigue, or cold, and particularly exposure during 
shipping. Under such conditions, microbes which live harmlessly in the luncs 
of sheep suddenly become capable of causing disease. The symptoms are those 
of a severe pneumonia and appear within a week following exposure- some 
animals die within 24 hours. The affected animals cough and sneeze and there 
18 a yellowish discharge from the nose and eyes. The temperature is high and 
there is complete lack of appetite. **' 

Animals sent to feed-lots, to shows, or those bought through a public market 
are most often affected. In the case of an outbreak, the best means of control 
is prompt separation of sick animals and great care in making them comfortable 
m a well-bedded and well-ventilated building. Noses and eyes should be kept 
clean with a solution of boracic acid. A veterinarian should be called as «oon 
as possible, if serious loss is to be prevented. Vaccination, bv a veterinarian of 
show or breeding animals which have to be shipped bv truck or rail is a >'ood 
preventive measure; this must be done at least 12 davs before expected exposure 
During shipping, animals should be well fed and not 'over-crowded Extremes of 
temperature are particularly dangerous and if possible should be avoided. 

Contagious Ecthyma (Sore Mouth).- This disease sometimes breaks out 
in range flocks and in feeding lots. Small blisters appear on the lips and gums 
of infected animals, and when these burst the disease will spread to the tongue 
and over the entire surface of the lips and nose. In severe cases the infection 
may spread to the stomach and lungs. 

As soon a s the disease appears, all affected animals should be isolated The 
scabs and blisters should be removed with a cloth soaked in a solution of boracic 
acid, and an antiseptic ointment should then be applied. Easily consumed 
concentrates and fresh water must be provided. 

When new stock is to be bought, the animals should be examined carefully 
belore purchase; further, they should be quarantined for several davs to avoid 
introducing the infection into the existing flock. 

Mastitis (Inflammation of the Udder).— The condition is not uncommon 
in the springtime shortly alter lambing. The udder becomes swollen hot and 
red m colour; the affected ewe usually walks with straddled hind-legs ' and doea 
not welcome the suckling of Iambs. A careful watch must be kept for this 
condition and affected animals and their lambs should be promptly isolated 
Bottle-feed the ambs for a few days on cow's milk. Milk out the udder at 
frequent intervals and apply cloths soaked in hot water several times daily 
N hen tins is not practicable, employ thorough massage, using oil va«eline or 

lard as a lubricant. It is essential to keep up the circulation ol blood in the 
udder; otherwise gangrene ("Blue-bag") will occur, and this can be treated 
only by surgical removal of the udder. 

Some Other Conditions 

"Stiff-lamb Disease ".—Insanitary conditions are conducive to lamb 
dysenterv and arthritis. When born on manure piles instead of on clean straw, 
lambs are exposed to infection. The lamb is even more seriously exposed if 
the navel cord is not swabbed with iodine, or if a dirty knife and no antiseptic 
is used at docking and castrating time. Keep the instruments in a solution of 
disinfectant, and use tincture of iodine freely. 

Plant Poisoning.— From time to time losses are caused by plant poisoning. 
Death camas appears to account for the majority of poisonings in the West and 
the water hemlock in Eastern Canada. There arc other poisonous plants, too 
numerous to be listed here. 

The chief reason for plant poisoning in sheep is lack of grass. It sheep are 
turned out in the springtime before there is an adequate growth, they will hunt 
for any available green feed. Keep them in, or supply supplementary feed 
until the growth of grass is well advanced. In times of drought a similar danger 
exists, and similar preventive measures become necessary. The destruction of 
poisonous plants by hand pulling is a practicable and effective control measure 
on most farms. 

Diseases Caused By Internal Parasites 

Regions East of Manitoba.— In the Eastern Provinces many worm parasites 
are encountered in sheep. However, research work has been successful in 
classifying the parasitic diseases of most importance, and an efficient system of 
control has been devised. 

Nodular Disease.— This is caused by young worms picked up with the grass 
from contaminated pastures. The worms enter the walls of the sheep's intestines, 
where nodules or knots are formed. When present in great numbers, these cause 
serious interference with health and may ruin many of the flocks in Eastern 

The eggs and young worms on the contaminated pasture lands are destroyed 
by the long winter frost. In the intestines of the sheep, however, the nodular 
worms develop to maturity during winter months and begin laying their eggs, 
which pass out and again contaminate pastures when the sheep are turned out 
in the spring. To prevent this recurrence and thereby protect the lambs from 
developing nodular disease, it is necessary to destroy the egg-laying worm in the 
adult sheep before the animals reach the pasture in the spring. 

Stomach Worm Disease.— This occurs in mid-summer, chiefly in lambs that 
become infected with 1,000 or more twisted-wire worms. The young worms are 
picked up from the grass in the same way as are the nodular worms. Most, but 
probably not all, of the eggs and worms on the pastures are destroyed by the 
winter freezing. 

Black Scours.— This trouble occurs in its most pronounced form among 
flocks where the acreage of pasture is limited and when pastures become dry 
and unnutritious in the autumn. It is caused directly by many thousands of 
almost invisible worms in the intestine and sometimes by a complicating hook- 
worm infection. Like the nodular and stomach worms, these parasites are picked 
up from contaminated grass. Some of the eggs and young worms are able to 
survive through the winter months, and consequently the pasture may be lightly 
infected in the spring-time. 


Based on the fact that the winter months have cleansed the pastures of 
nodular worm infection and have also reduced stomach worm infection to an 
almost negligible level, a highly effective medicinal treatment of breeding stock 
uotects the lands from contamination in the spring. A drug known as pheno- 
thiazine is used for this purpose, and a compound tablet has been developed 
m Canada and made available to all sheep owners. The system of control is, 
briefly, as follows: — 

1. Treat all the adult animals in the flock with phenothiazine tablet* 
either sometime between the first of February and one month before 
lambing, or, preferably, from four or more davs after lambing to 24 
hours before the flock is turned on to summer pastures. Do not treat 
pregnant ewes nearer than one month before lambing. 

2. Although this treatment usually prevents the occurrence of stomach 
worms as well as preventing nodular disease of lambs, watch for signs 
ot the stomach worm in July, August and early September. Infected 
Jambs may be fat, but they show pale eye membranes and move more 
slowly. When such signs appear, all the lambs should receive a 
treatment such as a drench of bluestone and nicotine (See page 7) 
capsules of tetrachlorethylene, a small dose of phenothiazine, or any 
other recognized stomach-worm remedy. Repeat in one month if 

3. Symptoms of diarrhoea in the autumn months are advance signs of 
future unthnftiness. Affected animals should be treated with pheno- 
thiazine, and if the grass is dry and sparse, supplementary feed should 
be provided. 

Instructions for Using Phenothiazine Tablets 
Phenothiazine tablets are obtainable through qualified veterinarians 
throughout Canada; also they may be obtained from the following- Canadian 
Co-operative Wool Growers Ltd., Toronto, and Weston, Ontario, Lennoxville 
Ouebec or Regina, Sask.; Wool Growers Association in Kamloops, B.C., Leth- 
bndge, Calgary, Lacombe, Edmonton, Hanna and Vermilion, Alta., and Maple 
Creek Sask.; Canadian Livestock Co-operative, Moncton, N.B • and the 
Canadian Livestock Marketing Board, Prince Edward Island 

Certain definite rules and procedures should be followed when giving this 
treatment. ° B 

Winter or Spring Treatment 

Treat all adult animals, including the ram. 

The number of tablets to be given depends upon the weight of the 
sheep, as follows: fe 

( ,l\ H P to , 100 „ Ib ' 3 com P° un d tablets (12^ grams each) 
(o) Over 100 lb, 4 compound tablets (12^ grams each). 

3 . Do not reduce the number of tablets recommended, particularly in flocks 
m which the nodular worm is prevalent. 

Summer and Autumn Treatments 

4. Flocks subject to diarrhoea or scouring in the autumn should be treated 
in September or at the first sign of diarrhoea in young animals 

(a) Grow-n Animals, 3 compound tablets (12^ grams each) 
ib) Lambs, 2 compound tablets (12£ grams each). 

5. For stomach worms in summer, give 1 to 2 tablets. 





How to Administer the Treatment 

nlnv3l he i™ atm Tu wiH be Safely and effici ently given if a veterinarian is era- 
W™, '+• , ^serywes of a veterinarian are not available, the following 

instructions should be closely followed:— 

1 • Pen the sheep quietly and securely for treatment. 

2. Do not fast sheep before or after dosing. 

3 . If treatment is given just prior to turning the animals to summer pasture, 
hold the flock for at least 24 hours to give the drug a chance to act, 
alter which there is no danger of contaminating the summer pasture. 
Have an assistant hold the sheep between his legs in such a way that 
the neck, not the shoulders, is between the knees. Avoid slippery floors, 
and place the sheep s hind-quarters in a corner against the wall The 
main object is to prevent the animal from sitting down, from moving 
the body from side to side, or from swinging its head sideways 
Use a mouth spreader, with a spread of about 2| inches to 2\ inches, to 
hold the mouth open. Administer the tablet when the animal is not 
struggling violently. The person giving the tablets opens the animal's 
mouth and inserts the mouth spreader so that the tongue is held 

orward underneath the lower bar of the spreader. Holding the tablet 
between the thumb and the first two fingers, the tablet is then brought 
2' do ?, to the root of the tongue by the fingers, where it is released 
and pushed over the hump " of the tongue by the centre finger. To 
ass st swallowing, the spreader is quickly taken out of the mouth 
and the assistant releases the pressure from the sides of the head and 
neck so that the animal can lower its head. The operation is repeated 
carefully for each tablet. Important^ tablets can be given to a 
sheep by an experienced doser in 30 seconds. 

;„* JX 0t f:~ Careless ° r inex Pert dosing may result in the accidental 
ntroduction o a tablet into the larynx, or windpipe; in such a case, 
the sheep should be given a drench of water and should be shaken with 
its head down. Always keep handy a drenching bottle filled with 
water Each person usually develops his own method of administering 
tablets. One substitute for the use of the fingers is to employ a 
balling gun made of a short piece of rubber hose pipe i" inside 
diameter with a simple wooden plunger. 


h«« SS^"? 6 haS b , ee u, USWl , for many tll( '^nds of sheep in Canada and 
has proved to be remarkably safe and efficient for general use. However in 
common with all drugs, it must not be used promiscuously; and when it has 

fir* t rfoS? ?o ef r ° n M C 1 ain R ° C \ h " b0ttCr t0 trcat two or three animal 
nrst in order to be sure that no peculiar conditions are present and that the 
mechanical part of the dosing can be done easily. 

Do- not treat pregnant ewes nearer than one' month to lambing. 

Discoloration of Wool 

rlnv T !'f C f ""r -° f treate i aniraal8 contains large amounts of a red stain for four 
days after dosing. In the case of ewes that are not shorn, if precautions are 
not taken a part of the fleece may be permanently stained. The flock should 
be kept in a well-bedded pen or yard. Avoid bare floors or yards with a 
heavy clay or otherwise impervious surface. If it can be arranged to have the 

£n J T an ? hcn tre u t l d 24 'T 1 " 8 before bei "g turned t0 summer pasture! 
danger of wool steins will be avoided. The young lambs are likely to become 

stained with urine in various degrees, depending upon how they nurse. Stains 
on lambs are not serious, as they will grow out and will not be noticeable by 

Western Canada 

From Manitoba to the Pacific Coast there is no nodular disease, and 
.stomach worm disease is not common. However, there are two types of 
diseases caused by worm parasite? that are of importance. One is a form of 
diarrhoea very similar to the "black scours" of the East; the other is a 
diarrhoea which chiefly affects yearlings in the late winter and early spring. 
As the infective forms of these parasites on the grass-lands are not completely 
destroyed during the winter months, the eastern system of prevention of pasture 
contamination as described on pages 4 and 5, does, not produce the same 
spectacular results. However, it is certain that a spring treatment of adult 
animals with phenothiazine, in somewhat reduced doses, is of definite value in 
reducing hazards of worm infections. Both forms of diarrhoea that are 
encountered in the West as a result of worm infections will respond to treatment 
with phenothiazine. As the medicinal treatment of large range flocks is not a 
simple matter, the owner must use good judgment and should obtain professional 

Other Worm Parasites. — The phenothiazine tablets mentioned are not 
effective against lungworms, tapeworms and liver flukes. Lungworms appear 
to cause disease only when other more serious troubles exist; fortunately the 
treatment recommended, together with good flock management, appears to 
make sheep resistant to this infection. Tapeworms are commonly blamed for 
many ills, but research has shown that such ills are actually caused by other 
parasites, particularly stomach worms and " black scour " worms. The copper 
sulphate and nicotine sulphate drench, however, removes many tapeworms. 

Liver flukes occur only in very small areas on the west coast and in Quebec 
and arc of little importance to sheep in Canada. In these small areas special 
treatments can be recommended. 

Insect Pests 

Blow-flies (Screw-worm Flies). — These insects, although not a major pest 
in Canada, do cause trouble in some regions. They deposit eggs in wounds or 
on soiled wool, and maggots which hatch invade the skin and underlying flesh. 
From late April to June is the worst period for infestation in British Columbia. 
The flies ordinarily breed in carrion; thus carcasses should be buried or burned 
whenever found. When the flies are prevalent, the flock should be shorn early 
and clip wounds should be dressed with an antiseptic. Scouring animals should 
i>c properly treated for worm parasites and the soiled wool clipped away. 

A formula used in South Africa for dressing maggot-infested wounds is a 
mixture of cottonseed oil, 45 parts (by measure, not weight), benzine. 40 parts, 
oil of pine tar, 10 parts, and carbolic acid, 5 parts. This tends to prevent 
further attacks as well as killing the maggots. In Australia a mixture of 
6 parts creosote, 20 parts turpentine, and 40 parts olive or raw linseed oil 
is used. If desired, plain benzine can be used to kill the maggots, but a fly 
repellent should then be applied to the wounds. 

The Nostril Fly. — This is an insect pest of some importance in all parts of 
Cajiada. The flies are related to the warble fly of cattle; they arc active during 
the summer months, when they deposit young grubs in the nostrils of sheep. 
These grubs craw] up into the sinuses, where they grow during the winter. 
They are present in about 90 per cent of all adult sheep and, unless in large 

numbers, do not cause trouble other than a discharge from the nose. Deaths 
attributed to this parasite are usually found to be due to other diseases, the 
causes of which are less easily seen by the sheep-owner. Nevertheless, in heavy 
infestations peculiar nervous symptoms are sometimes seen and losses may 
occur. In addition, the flies can be a continual source of irritation to the sheep 
during late summer, and some protection should be provided. 

Destruction of the grubs in the head is difficult, but some protection from 
fly attacks can be given to the flocks. The old method of smearing the noses 
of sheep with pine tar is partially effective; a way of inducing the sheep to 
renew the repellent is to bore holes into logs or troughs, fill with salt, and smear 
the edges with tar. A dark shelter, such as an old barn with the entrance 
darkened by sacking, is a good protection which is welcomed by sheep; on large 
ranges this can be replaced by brush shelters. A furrow ploughed in a pasture 
will be used by the sheep as a protection, although it is not as effective as a 
dark shelter. 

Keds and Lice. — The sheep ked (commonly but incorrectly named the 
" sheep tick ") is a common parasite wherever sheep are raised. This insect 
sucks blood and when present in large numbers causes unrest and consequent 
unthriftiness. It also causes breakages in the wool fibres and is a cause of 
soiled wool and losses from low grading. 

The biting louse is also a common cause of torment, with loss of flesh 
wool. The lice are very small and are not so readily seen by the owner. 

In order to prevent losses from these external parasites, all flocks should 
be dipped. In Eastern Canada, July and August are good months for dipping. 
or in the case of heavily infested lambs, as soon as the weather is warm enough. 
A second dipping may be necessary when heavy infestations are present; this 
should be about two weeks after the first. It is dangerous to dip sheep during 
cold weather, and when it is necessary to control these parasites during the late 
autumn or the winter a dry powder should be used. This is not as effective as 
dipping but will alleviate severe infestations. 

There are many commercial dips on the market, and those with a Pest 
Control Products Act registration number are reliable. The manufacturer's 
instructions, particularly in regard to amounts to be used, must be followed 
exactly. Handle the sheep gently and be particularly careful with rams and 
young bucks. Do not mix dipped and undipped sheep. 

The "Cunic" Drench for Stomach Worms 

The following treatment is one that, has been used for several years in 
many parts of the world. Its value in controlling the stomach worm has been 
well proved and, because the system of prevention through the use of pheno- 
thiazine tablets may not be possible under all conditions, the use of the drench 
is still to be recommended. 

Directions for Preparing the Solution 


Large 20 sheep 

Flocks or 1 

Crystals of Copper Sulphate (Bluestone) 3 oz. f oz. 

40 per cent Nicotine Sulphate 2 fluid oz. i fluid oz. 

Soft (or rain) water 1 Imp. gallon 1 Imp. quart 


Be sure that the Copper Sulphate crystals are clear and blue; discard 
whitened crystals. Heat a quantity of the water to dissolve the bluestone, in a 
vessel that is not bare metal, then add water up to full quantity. This 
solution will keep indefinitely in a glass, enamel or earthenware container, but 
it is better to add the 40 per cent nicotine sulphate only when it is about to be 

The Doses 

Fluid Ounces 

Adult Sheep 2 

Well-grown lambs 1 

Small lambs %-$ 

No fasting before or after treatment is necessary, but it is better to keep 
the animals away from water for a few hours, after the dosing. For weak 
animals the dose should be reduced rather than increased. 

Method of Dosing 

A suitable drenching bottle should be prepared so that the correct dose can 
be quickly and accurately measured into it. The sheep should be brought quietly 
into a small enclosure and the operator should dose each one by holding the 
head of the animal between his knees, thereby restraining it but not raising the 
head too high. A full half minute is needed for each animal; a strong flow of 
the liquid might cause some of it to enter the lungs, with serious results. 

Do not treat pregnant ewes that are within one month of lambing time. 
Do not treat lambs younger than six weeks. Sheep must always be handled 

Prepared by Science Service — Dominion Department of Agriculture. 

This pamphlet replaces the following pamphlets in the Wartime Production 
Series : 

No. 13 Control of the Sheep Ked. 

No. 44 The Prevention of Losses in Sheep Flocks. 

No. 51 Control of Certain Parasitic Worms in Sheep. 

Ottawa: Printed by Edmond Cviutier. Printer to the Kine's Most Excellent Majesty. 1942.